The present invention relates to a photovoltaic power generation roof, or a solar panel roof, and installation method thereof and, more particularly, to an installation method and structure of a photovoltaic power generation roof for installing the photovoltaic power generation roof easily, inexpensively, and electrically safely.
A photovoltaic power generation system utilizing a solar cell, a safe energy source which does not exert a bad influence on the environment, has been gaining the interest of many people. Easier installation, better cost-performance ratio, and better design of a photovoltaic power generation system have been urged; accordingly, a technique relating to a photovoltaic power generation roof which uses so-called solar panel roofing board, roofing boards with integrated solar cells, has been developed in order to replace a conventional installation method for installing a conventional solar panel on a roof.
In a photovoltaic power generation roof which uses he aforesaid solar panel roofing boards, a so-called reverse power flow connection is commonly adopted. In the reverse power flow connection, solar panels of the solar panel roofing boards are electrically connected in series to obtain a relatively high voltage from the connected solar panels 1, and the solar panels 1 are connected to a power system circuit 5 of an electric power company, as shown in FIG. 18. In such a case, a power inverter apparatus 2 (generally called an inverter) having a function of inverting DC (direct current) power into AC (alternating current) power, shaping the voltage waveform of the inverted AC power to that of the power system circuit 5, and providing the shaped AC power to the power system circuit 5 is provided.
For configuring a power generation system connected to a power system circuit of an electric power company in the reverse current connection as described above, it is preferred to ground the outer shell of a solar panel for the sake of electrical safety. Therefore, it is necessary to design a metal sheet and metal frame of the aforesaid solar panel roofing board to have a structure for grounding.
Conventionally, however, is disclosed in Japanese Patent Application laid-open (KOKAI) 9-199747, a solar panel roofing board has been developed while giving priority to performance of a solar panel and performance and design of the roofing board. Active development of a technique for securing electrical safety of the solar panel roofing board easily and inexpensively were left behind.